A wide variety of food products are prepared from cooked cereal doughs prepared from starchy cereal ingredients including corn, e.g., corn flakes R-T-E cereal. Generally, such cooked cereal dough based products are prepared from cereal doughs formed from cereal ingredient mixtures comprising de-germed, de-braned cereal flours. The selection of de-germed, de-braned cereal flours is due in large part to the stability problems associated with the utilization of whole grain cereal flours.
Whole cereal grains, i.e., individual kernels of grains, exhibit extended stability. However, upon milling to a whole grain flour the raw whole grain flour typically exhibits rapid deterioration. This rapid deterioration is due in large part to enzymatic activity, especially that which is associated with the lipid component. In part, for this reason, typical milling procedures mill the cereal grain so as to form separate streams of the bran, germ and starchy fractions since the lipid component is associated with the germ fraction. The raw starchy cereal flour fraction or white flour exhibits extended stability.
On the other hand, whole grain flours and products prepared therefrom are desirable due in part to their taste and nutritional benefits. Present consumer interest is great in products which provide the enhanced nutritional benefits and taste attributes of whole grain flours.
While all cereal grains exhibit stability problems to some degree, these problems are particularly severe in corn and oats. For corn, the problems are due in part to the high fat content of corn, e.g., 4% to 5%, relative to wheat, e.g., 2%. Oats are also high in oil content. The oil in oats is more evenly distributed than in corn where the oil is associated primarily with the germ fraction.
In order to retain the flavor and nutrition benefits of whole grain flours and to overcome the problems associated with the rapid deterioration of raw whole grain flours, the prior art includes a wide variety of techniques to provide whole grain flours, including corn flour, of increased stability. Some techniques are grain specific, e.g., the preparation of masa corn flour. In the traditional preparation of a masa flour, whole grain corn is cooked and steeped in alkaline water and milled, thereby resulting in a stabilized whole grain flour product. While useful, the alkaline water treatment imparts a characteristic flavor to the corn flour.
Another straightforward technique for preparing a cooked cereal dough from a whole cereal grain is to cook the flour to form a cooked cereal dough immediately after milling the whole grain into a flour. While useful, due to the extremely rapid rate of deterioration after milling, even a time delay after milling of a few hours can result in a product exhibiting unacceptable deterioration. In large scale commercial practice such delays are frequent and difficult to avoid entirely.
Still another long known technique described in the prior art is to form a "rebuilt" whole cereal grain by recombining the different parts of the grain after separation and individual treatments for stabilization. For example, U.S. Pat. No. 876,662 entitled "Cornmeal Product" (issued Jan. 14, 1908 to E. W. Simons) discloses a method involving separating the germ and heat treating followed by recombining the treated germ with other corn flour components.
Another technique is to mill whole cereal grains into whole cereal flours and immediately thereafter treat the whole cereal flour such as with heat to produce a stabilized whole cereal flour.
While stabilized whole grain flours are useful, it would be desirable to have a whole grain kernel which has been treated such that upon subsequent milling to form a whole cereal flour the resultant raw flour would exhibit enhanced storage stability. Such a stabilized whole kernel flour would provide the industrial user even greater convenience since whole grains are easier to handle and transport both between facilities and within facilities than flours. Fortunately, the prior art includes methods for providing such stabilized whole cereal grains. For example, U.S. Pat. No. 4,737,371 (issued Apr. 12, 1988 to G. N. Bookwalter and entitled "Process For Stabilizing Whole Cereal Grains") discloses a low temperature (95.degree. to 110.degree. C.), low pressure (e.g., atmospheric) long hold time (e.g., 12 minutes) process for treating whole grain kernels.
Surprisingly, still another method has been discovered for treating whole cereal grains that upon milling provide raw whole cereal grain flours of extended storage stability. In contrast to the methods disclosed in the '371 patent, the present methods involve a high temperature, high pressure, rapid heat treatment step. The principal advantage of the present invention is its simplicity. Another advantage of the present invention is the ability to use cereal processing equipment which is readily available. Still another advantage is that no pretreatment adjustment of moisture content of the grain is required or a subsequent drying step.